Whenever one wants to use RDFa 1.1 one uses [HTML5](/blog/529/). In HTML5 one has to say in the HTML Tag which Version of HTML one uses, i.e. [HTML](/blog/528/)+[RDFa 1.1](/blog/881/) and one can define Namespaces that might be required within the Document.
RDFa Primer 1.1 [http://www.w3.org/TR/xhtml-rdfa-primer/]
http://www.w3.org/1999/02/22-rdf-syntax-ns#">](http://www.w3.org/1999/02/22-rdf-syntax-ns#)]
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